WEATHER NEWS: Supermoon may interfere with views of Perseids, the ‘best meteor shower of the year’
The Sturgeon full moon, the third supermoon of the summer, is to take its place on the grand celestial stage Thursday night. This would typically thrill avid skywatchers, but many people will instead be looking up to the sky hoping to see the annual Perseid meteor shower, which is forecast to reach its spectacular mid-August peak early Friday morning.
Like other skyward phenomena, you’ll have your best chance to see the Perseids — which NASA calls “the best meteor shower of the year” — during the natural darkness of nighttime and where skies are free of light pollution. Even in major metropolitan areas, the intensity of the meteor shower, which launches 50 to 100 meteors per hour, can typically be seen during the overnight and early-morning hours.
Because a supermoon brightens the skies, its simultaneous presence may cut the number of visible meteors in half.
In D.C., moonrise Thursday is at 8:26 p.m. Eastern. The moon is officially full at 9:36 p.m. Eastern.
The moon is always reflecting light from the sun when it appears in the sky. Supermoons, which occur when a full moon is at its closest to Earth in its orbit, known as perigee, appear even larger and brighter than normal.
Skywatchers everywhere should be able to catch a glimpse of the Perseids even with the supermoon’s interference, although they may need to prepare more — and be a little luckier than usual.
Sky and Telescope magazine says that while ordinary Perseid meteors might be harder to see because of the supermoon, fireballs should still be quite visible. A fireball is a meteor that streaks across the sky atthe same brightnessasor a greater brightness than the planet Venus, according to the American Meteor Society, often sparking dazzling displays of color.
Larger chunks of comets produce more fireballs, so it makes sense that the Perseids fire off many of them. The parent body of the Perseids, the comet Swift-Tuttle, is quite large at 26 kilometers. A team led by NASA’s Bill Cooke, who heads the agency’s Meteoroid Environments Office, recorded 568 fireballs coursing through the sky during showers between 2008 and 2013, the most of any other meteor shower in that time frame, according to Sky and Telescope.
To optimize the chances of seeing the Perseids — even without being lucky enough to catch a bright fireball — there are somebest practices for seeing a vivid night sky.
One recommendation from Earthsky.org is to avoid the light interference of major cities and find a dark space away from highly developed areas. Ideally, your skywatching spot would also be in a moon shadow, which allows you to see a slightly darker view of the night sky.
The reflection of the sun’s light off the Moon does cast shadows on Earth, and a supermoon will cast even more dramatic shadows. According to Earthsky, the ideal spot to be in a moon shadow would be on a plateaued area with tall mountains blocking the moon’s light. For those without mountains nearby, it would suffice to find a grove of trees or tall buildings that block the moon’s light while still allowing you to have a clear view of the night sky.
Clear skies over large parts of the country will provide unobstructed views of the moon and any meteors, but some cloud cover will interfere right along the West Coast, in parts of the Rockies, the Upper Midwest and the Southeast.
For those less inclined to stay awake into the wee hours of Friday morning to catch the peak of the meteor shower, some meteors should still be visible earlier in the night. Skywatchers might also see an “earthgrazer” meteor, a rare type of meteor that most commonly appears in the late evening.
Earthgrazers are unique because they approach the planet at a very shallow angle, which allows them to travel long distances across the upper atmosphere, even sometimes exiting the atmosphere and reentering space rather than burning up in Earth’s atmosphere, according to NASA Meteor Watch.
Because of the supermoon, expectations for seeing the Perseids on Thursday night should be tempered. But with the chanceto see a radiant fireball, a long-lasting earthgrazer or any of the dozens of meteors expected to pass through the atmosphere regardless of the Sturgeon moon’s interference, stargazers shouldn’t leave empty-handed.